Within the area of still and motion picture cameras image stabilization has always been an issue. Within the context of the present application image stabilization may refer to the reduction of the effects of motion during an exposure time, i.e. a motion that would otherwise result in a motion blur. It should be noted that the effects of the motion may depend on the type of shutter. In a motion picture application, such as when a video camera is used, each individual image may be quite sharp, though due to unwanted motion the recorded video sequence as such may be difficult to follow. A typical “unwanted motion” may in such a case be caused by shaking or vibration, and this may be handled as well within the context of the present application. This type of motion often requires a more complex approach since there may be both an unwanted motion and an intended motion, e.g. a panning motion. In these situations a digital image stabilization may be applied as the only measure or as an additional measure to an optical image stabilization.
The present disclosure will relate to an optical image stabilization mechanism, i.e. a technique in which a component in an optical path of the camera is moved in order to compensate for the unwanted motion. The component moved may typically be a lens element or an image sensor.
It is known to suspend optical components resiliently and controllably, wherein ball bearings supported by a plate (generally one plate per ball) enables a free motion in a plane, see e.g. US 20120027391. As discussed in the cited document the plate and ball construction may be susceptible to wear over time, either affecting the shape of the ball or the surface of the plate, both affecting the performance of the image stabilization. A solution disclosed in the cited document is to form the balls from a ceramic material.